1. Technical Field
The present invention relates to a projector for a viewer to recognize a projected image as a stereoscopic image, a projection system, and a control method of the projector.
2. Related Art
In order that a viewer may recognize an image displayed by a projector as a stereoscopic image, various systems for right eye and left eye of the viewer to visually recognize respective different images (parallax images) have been proposed. As one of the systems, for example, there is a system in a mode in which a projector time-divisionally and alternately projects images for left eye and images for right eye. In this mode, the viewer may recognize stereoscopic images by viewing the images through shutter glasses for the left and right eyes alternately opening and closing in synchronization with switching between images. In a stereoscopic video system disclosed in Patent Document 1 (Japanese Patent No. 3101542), images are projected on a screen from a projector, and synchronizing signals (control signals) for controlling opening and closing of shutter glasses are output from an output unit of the projector, reflected by the screen, and received by the shutter glasses. Thereby, switching between images by the projector and opening and closing of the shutter glasses may be synchronized.
However, many projectors have high degrees of freedom of installation such that they may be mounted not only on a desk but also on a ceiling and a projection position of the images may be adjusted by a lens shift function or the like. Therefore the projectors may be used in various installation conditions. On the other hand, in the stereoscopic video system disclosed in Patent Document 1, an output direction of the synchronizing signal is determined by the installation condition (direction) of the projector, and there is a problem that a location where the shutter glasses can receive the synchronizing signal is limited depending on the installation condition of the projector.
Further, a system in a mode in which an output unit of a synchronizing signal is separated from a main body of a projector and the main body and the output unit are connected using a cable has been proposed. In this mode, the synchronizing signal may be transmitted in an arbitrary direction regardless of the installation condition of the projector and shutter glasses may easily receive the synchronizing signal. However, the output unit and the projector main body are separated and handling is complicated. Furthermore, in this mode, the main body and the output unit are connected by the cable, and an appearance after installation is degraded.